It's interesting how a claim can be built on so little evidence. What were Romans doing in Ohio in the second century AD? The author states the coins were found as if they were leftover from a long disintegrated leather pouch. Who made this determination? Was it the construction worker who found the coins? Was it someone from the museum based on a 34 year old description? That's pretty thin, though admittedly not impossible.
It is possible an isolated Roman ship got blown into the Atlantic and accidentally arrived in the New World. But how did they get 1,000 miles inland?
At the least, the claim Romans came to America is an extraordinary claim. A number of very smart people have addressed this sort of thing and Carl Sagan may have put it best "extraordinary claims require extraordinary proof." I think that applies here, we cannot say ROmans did not come to America, but we need a lot more proof.